Circuit control device



July 9,1940. w. c. AUSTIN ET AL CIRCUIT CONTROL DEVICE 1 Filed Aug. 15, 1938 INSULAT\ON "I'I'IIII" "I'I'l wllllllllllll il/ alier Clyde $152572 INVEN'TORSI l6 ig ebsier Hill I LATION ATTORNEY.

Patented July 9,1940

UNITED STATES PATENT OFFICE CIRCUIT CONTROL DEVICE Walter Clyde Austin, Burbank, and Webster Hill,

Los Angeles, Calif. i

Application August 15', 1938, Serial No. 224,880

4 Claims. (01. zoo-s This invention relates to a circuit controlling shaped packing |8a fastened to a piston rod I9 by device, and more specifically to that type of device means of the opposed plates Mb, I 8b and opposed used for the time control of electric circuits. nuts I86, I80, threadedly received on the end por- An object of the invention is to provide an imtion of the rod. The other end of the rod is also proved control means capable of making or dis threaded, carrying a knurled nut 26 and also a rupting a circuit after a predetermined interval lock nut 2| to hold the nut 20 securely on the rod has elapsed. in various positions of adjustment; wherefore the A further object of the invention is concerned time control of the circuit can be varied, in a with an improved device capable of controiling a manner to be hereinafter explained.

10 circuit over a predetermined interval of time, and The Piston rod l9 extends ou t e eaf eon- 10 in which said interval can be varied. tact spring IS in order that inward positioning of Still another object of the invention involves the circuit breaking nuts 20, 2| can move it away the provision of an improved device for controlfrom the binding post flange l2a. Such inward ling a circuit in dependence upon the escape of pos on ng is obtained under the influence of a an entrapped fluid from the device. return helical spring 22 abutting at one end 15 Another object is to provide a time control against the piston and at its other end against circuit device that is free from complexity and the insulated cylinder end plate I3. It will thereeconomical to manufacture. fore be apparent that the spring will normally Other objects and advantages of the invention urge the piston and the circuit breaking nuts on will become apparent from the following descripe end f the r inw y, as hhw in Fi 20 1 tion when taken in conjunction with the drawing, but. that outward movement of the knurled nut inwhich: to the dotted line position will permit the leaf Fig. 1 is a diagrammatic view, illustrating on Sp l5 to e gage with the binding post l2 to application of the invention; complete the circuit, at the same time compress- 25 Fig. 2 is a perspective view of the time conin t he l spr wh h w u imm diat ly 25 trolled circuit device; return the parts of the mechanism to their initial Fig. 3 is a longitudinal section of the device; circuit breaking positions were it not for the pro- Fig. 4 is an end elevation of the device, as seen vision of a time delay mech incorporated from the right of Fig. 3; and within a device.

Fig. 5 is a diagrammatic view, showing another To et inward movement of the piston I8 30 application of the invention, 1 and nuts 20, 2| on the end Of the rod, the rod 19 is In the specific formof the invention disclosed Provided with a bore I911 extending entirely in the drawing, it is desired to control the flow of therethrough fr m the h P e end of the current through an electric circuit. In furtherpiston t e t readed bore 0a in the knurled nut.

ance of this objective, a lead l0 can have its end As the piston a nut are e cted, air can fiow portion ii fitting within a binding post l2 se- P the eupeshaped Packing om the low cured to a cover or end plate l3 for a cylinder i4. Pressure end of the cylinder to the high P ess e The cover is made of insulating material and end thereof. This is readily accomplished in view ries a leaf spring contact 15 adapted to complete of the ease with which the cylinder contacting or disrupt the circuit by making or breaking con D S 0f the packing can o p under t e 40 tact with the flange l2a on the binding post. .The pressure of the air flowing in the manner indiinsulated cover is secured to a flange a on the cated. However, as the helical sprin tends to end of the cylinder by means of the crews [6 return the piston to its initial position, the air at threadedly received in tapped holes I! in the the hig pressure y de nd l expand the flange. One of these screws can serve as an anpacking against h Cylinder Walls p ve 45 chor for the leaf spring, which has an extended s e there'areund. the y p tho air mo'veportion ISa-for receiving a second lead lfiaior ment being, through the h ll w p n rod l9 and conducting current to or from a circuit controlled thmugh the nuts 2| 1 the p re. For mechanism (shown in Figs. 1 and 5 the purpose of restricting the flow of air, a small Engagement between the leaf spring I! and plate 23 is inserted in the bore of the knurled nut the binding post flange Ila is controlled by atimso that it will tend to snugly engage the end of ing mechanism, part of whichis contained within the rod. In addition, delay in the escape of air the cylinder and part outside of the insulated is obtainable by the packing eflect produced by cover plate. The portion within the cylinder inthe threaded connection between the nuts 20, 2|

65 cludes a piston I8 consisting preterm! of a cup and the piston rod it. It will be appreciated that the air must pass through the piston rod and then around the undulated threads prior to its escape to the atmosphere. It the eflects of the threads were to be minimized, ease of air escape could be readily provided by forming a flat side l9?) along one portion of the piston rod.

One application of the invention is disclosed in Fig. 1, in which a propeller of a model aeroplane (not shown) is driven by a small internal combustion engine 3| that is supplied with fuel from a suitable source (not shown). Such aeroplanes are designed to operate over relatively short intervals of time, their period of flight presently being governed by the extent of the fuel supply. 'To definitely determine the flight time and to render it independent of the fuel supply,

the circuit controlling device of the presentin vention can be incorporated in the ignition sys-- tem of the internal combustion engine.

The controlling device is placed in series be-** tween a battery..32 and the usual coil or autotransformer 33 used in ignition systems, with the usual make andbreak 34 interposed in the line for insuring the induction of a high voltage into the secondary circuit of the coil, in which cirs cult is included the engine spark plug 35. A condenser 36 is connected across the make and break device for preventing arcing.

When flightof the aeroplane is desired, the knurled nut 20 is grasped by the fingers and the piston and piston rod pulled with it outwardly against the action of the helical spring, permitting contact to be made between the leaf spring l5 and the binding post l2, current flowing through the coil 33 as governed by the make and break 34 to induce a spark across the spark plug terminals. The compressed helical spring 22 will immediately urge the piston, rod and knurled nut towards circuit breaking position, but its influence will be delayed through the resistance offered by the relatively slow escape of air through the piston rod and knurled nut. The nuts on the outside of the cylinder will therefore be moved inwardly very slowly, the engine being operated until the leaf spring is moved from the binding post by its contact with the lock nut. The time of flight can readily be varied by threading the knurled nut and lock nut on the rod to alter their positions thereon, and therefore, the distance that the rod must be returned by the helical spring before the leaf spring contact will be moved from the binding post.

Fig. 5 discloses a further mode of using the invention, as by incorporating it in series with an incandescent light bulb 377, the current to the bulb being disrupted after a predetermined period of time, depending upon the setting of the leaf spring moving members 23, fit.

While the specific embodiment has been shown applied to the breaking of a circuit after a predetermined time interval, it will be apparent that the control parts can be easily arranged so that the circuit will be completed after the passage of such interval, as by causing the leaf spring to engage with the binding post upon inward engaging movement of the knurled nut and locked nut.- It will also be appreciated that circuits other than electric ones can be controlled by the timing device, including valve mechanism, parish ing meters, paper towel dispensers, lawn sprinkler systems, etc.

It is to be understood that the speciflc embodiment disclosed on the drawing is merely illustrative of the invention, which is best defined in the appended claims.

We claim:

l. A circuit control device comprising a cylinder having a leaf spring switch secured thereto and insulated therefrom, a spring operated piston mounted in said cylinder, a fluid conveying hollow piston rod secured to said piston, said rod having its inlet end in fluid communication with the high pressure side of said cylinder and its outer fluid discharge end projecting from said cylinder, and valve means on the outer end of said rod for controlling the flow of fluid from the projecting discharge end of said rod and operating said switch on a retracted movement of munication with the. high pressure'side of said cylinder-and its outer discharge end projecting from said cylinder, and an adjustable nut on the outer end of said rod forcontrolling the flow of fluid from the projecting discharge end thereof and also for the operation of said switch on an inward movement of said piston.

3. A circuit control device comprising a cylinder closed at oneend, a plate formed of an insulating material secured to the open end of said cylinder, a terminal binding post secured to said plate, a leaf spring terminal secured to said plate its free end normally out of engagement with said binding post, a piston mounted in said cylinder, a hollow piston rod secured to said piston and in communication with the high pressure side of said cylinder and having a flattened outer end portion projecting beyond said insulating plate, .anexpansion spring mounted in said cylinder between the piston and insulating plate forforcing .the piston inwardly, and an adjusting nut threadingly engaging said piston rod for regulating the flow of fluid from said cylinder. and-for operating said leaf spring to open the circuit when said piston has been fully retracted.

4. 'A circuit control device comprising a cylinder closed at one end, a plate formed of an insulating material secured to theopen end of said cylinder, arterminal binding post secured to said plate, a leafspring terminal secured to said plate with its free and normally out of engagement with said binding'post, a piston mounted in said cylinder, a hollow piston rod secured to said piston and in communication with the high pressure side of said cylinder and projecting beyond said insulating plate, an expansion spring mounted in said :cylinder between the piston and insulating plate for forcing the piston inwardly. and an adjusting nut threadingly engaging said piston rod for regulating the flow of fluid from said cylinder and for operating said leaf spring to open the circuit when said piston has been f y retracted.

WAL'IER CLEE AUSTIN.

WEBSTER HILL. 

